The present invention relates to a feeding device for feeding fuel.
Feeding devices of the above mentioned general type are known in the art. In known feeding devices the fuel is fed from a fuel tank, for example to an injection system of an internal combustion engine of a motor vehicle. Such a feeding device is disclosed for example in the German patent document DE 44 44 854 A1. In this device the feed pump is driven by an electric motor and the fuel flows from the feed pump through a pre-filter and then is supplied after the feed pump under the feed pressure through a main filter. These components are arranged in a filter casing with a removable cover. The electric motor and the feed pump are located in a central chamber, and the main filter is located in a ring chamber which is arranged concentrically to the main chamber.
Communications for tubular connections or pressure hoses are provided on the cover of the filter cup. The fuel is supplied through them to a connection flange on the fuel tank. The feeding device thereby forms a complete feeding module which can be arranged directly in the fuel tank. The fuel in the fuel tank can be aspirated from below on the feeding module and from above from the connecting flange on the cover of the fuel tank and supplied through a supply conduit to the internal combustion engine.
With such an arrangement, it is important that no electrical discharge can take place, which can lead to an ignition of fuel or the fuel-air mixture in the tank. The corresponding withdrawn of electrostatic charges is difficult to execute with the components which are mainly composed of synthetic plastic and either are non electrically conductive or have poor electrical conductivity.